Being thrust into the world of genetics is an eyeopener. It is interesting and mind-blowing how we are all created – each of us so unique. DNA is an incredibly powerful thing, and can tell almost everything about an individual.
In a previous post I mentioned the Genetic Information Non-discrimination Act (GINA), and the important role it plays. Genetics is an area full of information waiting to be uncovered…life-saving information. Fortunately I live in a state (NC) that is ahead of the game where genetic discrimination is concerned. Non-discrimination policies for positive results for the BRCA mutation have already been in place. GINA simply enforces them all over the U.S. – people DO move around after all.
The genetics of breast cancer is vital! Genetic testing offers the hope of a longer and more productive, happier life, and can help the appropriate patients achieve these goals. My appointment with my oncologist and geneticist was a true eye-opener. Some of the information was not new, while other really educated me even more about my decision to be tested.
- The inheritance of a BRCA1 or BRCA2 mutation places a female carrier at an 87% risk for breast cancer.
- It is a 40%-60% risk for a second breast cancer if a woman has previously had breast cancer.
- The lifetime risks for ovarian cancer are 20-40% for BRCA1 carriers and 15-30% for BRCA2 carriers.
- A carrier parent has a 50% chance of passing the mutation on to each offspring.
- BRCA1 and BRCA2 mutations are inherited equally through the maternal (mother’s) or paternal (father’s) family lines. Therefore, the family history of breast and/or ovarian cancer on the father’s side is as important as the history on the mother’s side of the family.
- If testing reveals a confirmed disease-causing mutation (positive result), the future risk for cancer is reasonably well defined, and there are options available.
So, what are BRCA1 and BRCA 2 exactly?
The Easy version (easy -really?) : The BRCA1 and BRCA2 proteins are both involved in the repair of DNA damage and other cellular processes critical for maintaining genomic integrity. The function of the BRCA1 and BRCA2 proteins is the protection of the cell from the development of cancer. Cancer is caused, in part, by an accumulation of mutations in the cell cycle regulatory and DNA repair genes.
The More Difficult Version (as explained by my geneticist) : Humans have two copies of every gene, one copy from each parent. In the case of tumor suppressor genes (BRCA1 and 2 are both tumor suppressor genes), both copies of the gene involved in maintaining genomic integrity must be mutated before tumor formation begins. The majority of genes are not inherited but acquired over time by random chance, exposure to hormones, diet, and environmental carcinogens. Inherited breast cancer is different in that one mutated copy of the BRCA1 or 2 genes is germline (or inherited) in an autosomal (or non-sex /X &Y chromosome) dominant fashion. When a cancer of the breast occurs in a member of a high-risk family, the remaining normal copy of the gene is lost through a mutational process.
Essentially, The mutation of the BRCA1/2 tumor suppressor genes causes the cell to lose its protection from the development of cancer.
I highly recommend asking about genetic screening if there is a significant reason. Most people are fearful of the cost surrounding the testing. I was shocked…SHOCKED…when I was told in the state of NC (at the cancer center) the test would be “taken care of” if insurance did not pay for it. WOW! If the test needed to be sent to Myriad (the company that owns the patent for the testing) my maximum out-of-pocket would be $375 for the portion insurance would not cover.
Now I wait.
